package task;
//Description:一些作业题
public class Task3_1 {
    public static void main(String[] args) {
        int frequency = 0;
        for (int i = 1; i <= 100; i++) {
            int a = i;
            while(a > 0) {
                if (a % 10 == 9)
                    frequency++;
                    a = a / 10;
            }
        }
        System.out.println(frequency);
    }
}
